An Efficient Gain Enhancement Approach for 60-GHz Antenna Using Fully Integrated Vertical Metallic Walls in LTCC

The gain of antenna array operating at 60 GHz using low temperature cofired ceramic (LTCC) technology is enhanced, by introducing a simple, low-profile, and low-loss structure. Part of the radiated waves in the antenna array's E-plane is in-phase reflected, by fully integrated vertical metallic walls. Consequently, an improved gain performance can be obtained. The substrate integrated waveguide slot antenna array is implemented for demonstrations. Those vertical metallic walls, created by cofabricated open-air cavities, are placed at either side along the H-plane of slot radiators. Investigations were conducted on those key parameters of a single-slot antenna with two vertical metallic walls, in order to have a better understanding on the effect of the walls. Two prototypes, which are a 1 × 8 (1-D) and a 4 × 8 (2-D) waveguide slot antenna array, have been separately developed for verifications. The dimensions of the developed antenna arrays are determined based on a compromise between the performance and the fabrication restraint in the LTCC process. Both antenna arrays can efficiently transmit data within a 1000 MHz (59.5-60.5 GHz) bandwidth for some narrow band applications. When compared with conventional antenna arrays without metallic walls, the proposed approach can achieve gain enhancement of about 4.4 dB for the 1-D case and 2.5-3.1 dB for the 2-D case, across the impedance bandwidth.